CN103907360A

CN103907360A - System and a method for streaming pdm data from or to at least one audio component

Info

Publication number: CN103907360A
Application number: CN201280053400.8A
Authority: CN
Inventors: C·E·弗斯特; G·博加松; M·德吕京斯基
Original assignee: Knowles Electronics LLC
Current assignee: Knowles Electronics LLC
Priority date: 2011-09-01
Filing date: 2012-08-27
Publication date: 2014-07-02
Also published as: KR101588003B1; US20130058495A1; KR20140060556A; DE112012003663T5; WO2013033001A1

Abstract

An electronic circuit, a digital audio component, an interface system and a method for streaming PDM data from or to at least one audio element are provided. The electronic circuit comprises a VDD connection for receiving a VDD potential, a GND connection for receiving a potential numerically lower than said VDD potential, a CLK connection for receiving a clock signal having a high and a low part, a DATA connection for communicating said PDM data to or from a host and/or another such electronic circuit, an L/R connection for receiving a DC potential designating whether to communicate substantially synchronously with said high part or said low part of said clock signal. The electronic circuit further comprises an I/O circuit configured for communicating control data via said L/R connection.

Description

For from or to the system and method for at least one acoustic component flow transmission PDM data

The cross reference of related application

The application is the U.S. Patent application No.13/224 submitting on September 1st, 2011,068 continuation application, and require its priority, be incorporated to by reference its content at this.

Technical field

The present invention relates to electronic circuit, digital audio parts, interface system and the method for the electronic equipment such as mobile phone or laptop computer, comprise the audio system such as the digital audio parts of microphone assembly and/or loudspeaker assembly, wherein this digital microphone wind part picks up and can listen or other speech simulation signal convert them to the particularly digital electric signal of PDM signal, and wherein digital loudspeaker parts send the digital electric signal of PDM signal particularly and convert them to respectively and can listen or other speech simulation signal.

Background technology

Communication technology progress developed rapidly in recent years.Consumer is using more and more electronics to move with static and is communicating by letter, and comprises such as the acoustic component that audio-frequency function is provided of headphone, loud speaker, microphone, amplifier for being connected with other audio frequency apparatus, television set, speech recognition etc.These parts use in the more and more less equipment of being everlasting, such as the cell phone of cell phone, network enabled, personal digital assistant (PDA), handheld computer, laptop computer, such as flat computer or the Miniature digital audio connector of pad or have any other similar devices of printed circuit board (PCB).Use digital audio parts to make it possible to utilize electronic digital circuit and advanced signal processing to carry out acceptable audio reproduction.

That is developing relates to microphone or loudspeaker applications MEMS (micro electro mechanical system) (MEMS) for portable and technology Static Electro subset.MEMS technology makes it possible to build little mechanical part on the substrate such as printed circuit board (PCB).Microphone MEMS comprises that size is the mechanical organ of 1 to 100 micron (0.001 to 0.1mm) generally, makes common 1mm be " stick " to microphone element and electronic circuit thereof and provide in the encapsulation of housing, air chamber and protection to the microphone assembly in the magnitude range of 3mm or assembly.These acoustic components have little size and are therefore suitable for being included in little and/or thin electronic equipment.Aspect this, these acoustic components can be included in various types of electronic equipments and system; Such as computer, for example desktop computer, laptop computer, flat computer, handheld computer, personal digital assistant (PDA), global positioning system (GPS), safety system; Communication equipment, for example cell phone of cell phone, network enabled, cordless telephone, beep-pager; The ancillary equipment relevant with computer, for example printer, scanner, monitor; Amusement equipment, for example television set, broadcast receiver, satellite radio, stero set, tape and computer cd player, digital camera, camera, cartridge VTR, Motion Picture Experts Group, audio layer 3 (MP3) player, video game machine; Listening equipment, such as hearing aids, earphone, headphone, Bluetooth wireless earphone, insert earphone, UWB wireless headset etc.Other example of equipment is possible.In addition, provide compact audio parts to reduce or eliminate significantly the impact of electromagnetic interference EMI.Because these acoustic components are little and easily manufacture, so reduced manufacturing cost and strengthened reliability.

PDM (pulse density modulated) signal is the bit modulation digital signal using in audio area, and is defined herein as the digital signal that comprises audio content.PDM is the modulation format that represents the analog signal such such as audio signal by numerical data.In PDM signal, from different in PCM (pulse code modulation), particular amplitude value is not encoded as pulse.On the contrary, the relative density of bit pulse is corresponding to the amplitude of analog signal.In contrast, PWM (pulse width modulation) is analog signal, and the width of pulse is used to indicate signal value.

At present, be called as PDM interface for output example as the actual interface standard of the common sector application of digital microphone signal (not being the standard coming into the open).This interface or industry standard be characterised in that its low complex degree and the microphone assembly that correspondingly obtains on the stitch of the smallest number that needs.The PDM interface of digital audio parts comprises five stitch and can be defined as at least comprising:

VDD: for the supply voltage of microphone assembly, conventionally select clear and definite high potential, such as 1 near 4V, be generally 1.8V.

GND: for the electrically electromotive force of microphone assembly, wherein, GND or be defined as potential voltage lower than the voltage potential providing on VDD stitch, for example, such as the definition of the zero potential of the VDD electromotive force with respect to used.The numerical value of GND and VDD can be for defining this lower (GND) and higher (VDD) electromotive force.

CLK: for the clock input signal of microphone assembly.Normally used frequency range comprises from 1 to 7MHz, for example, and 2.4MHz.For example, independent external clock reference or host-processor self can produce these clocks.Conventionally, sleep mode operation is possible, for example, selects by the CLK signal lower than 100kHz.

DATA: from the data flow of microphone assembly output, comprise the audio content with the form of a bit pulse density modulation PDM signal.Output can be effective in of a clock cycle phase place, and in other phase place, the output of DATA is tri-state, and it allows output also to adopt high impedance status outside 0 and 1 logic level, has effectively removed PDM signal from the output of parts.This allows multiple circuit to share identical output line.This makes it possible to add for example two microphone assemblies to same data conductor.

L/R (left/right): for the input selector of select effectively-tri-state clock phase, for example often select by L/R be connected to VDD with the high phase place that enables clock to adopt the effective phase place of data and will become the low phase place of tri-state.Other electromotive force is possible, and for example, L/R can be connected to GND or another electromotive force firmly, and it has changed the wherein effective clock phase of data.Thereby, microphone assembly can based on L/R stitch select level and drive PDM data at rising edge or the trailing edge of clock.Microphone assembly can be multiplexing to carry out according to the twice clock control of the speed of clock.In the time that definition digital level provides low or 0 bit to be also to provide height or 1 bit, the digital voltage standard of observing is known in the art, and some representative values are to be low and to be high higher than 65%VDD lower than 35%VDD.

Can use other electromotive force that is different from VDD and GND, wherein GND is the electromotive force that is defined as ground or zero potential, that is, the magnitude of voltage GND of definition, it is lower than the numerical value of VDD.

When such as the such acoustic component of microphone assembly during by miniaturization as mentioned above (manufacturing littlely of to meet manufacturer and the client request for miniature and effective parts), PDM interface is particularly useful, this be because welding, combination or by this undersized surperficial microphone assembly, (while being connected to PCB such as the microphone assembly or the ECM (electret capacitor microphone) etc. that comprise the element based on MEMS, the connection of relatively low quantity is favourable.

For the microphone element from described PDM interface (such as MEMS microphone element) sends PDM signal, often provide the electronic circuit integrated with the microphone element that microphone assembly is provided.This electronic circuit can be integrated electronic circuit, such as ASIC (special integrated electronic circuit), embedded-type electric electronic circuit or external electronic circuit etc., it is for example by using barrier film and/or magnetic surface for example to convert the simulated audio signal receiving from microphone element to digital audio and video signals, with from streaming stitch (, the DATA stitch of PDM interface) read, or read in the situation that audio components is for example loudspeaker assembly.Microphone assembly (being the combination of microphone element and electronic circuit) often provides and/or provides on PCB and/or metallic packaging housing and/or inside together with PCB and/or metallic packaging housing, and be incorporated to and have in chip, wherein stitch connects from parts sensing outside.

Develop the various chips design alternative for electronic circuit is provided, comprised special integrated electronic circuit (ASIC); Application Specific Standard Product (ASSP); And structured ASIC, structured ASIC comprises the combination of ASIC and FPGA (, field programmable gate array).

In voice applications, provide the digital electronic system of audio interface can require processor parts, be called main frame, it is specifically programmed as controlling acoustic component, for example, pattern changes or for example at the gain setting such as in microphone assembly or the such transducer of other input element, can drive with digital audio and video signals after treatment the output block of one or more loud speakers, amplifier, earphone or other main frame or other types simultaneously.In the audio system such as being arranged in laptop computer or mobile phone, digital microphone wind part often needs to communicate by letter with host-processor and sets or receive order from main frame can change internal gain, refers to below for further describing.Main frame is defined as the processor of digital processing ability at this.Example is CODEC or application processor.

Which microphone assembly the bit replacing of understanding audio content for processor or main frame belongs to, and the clock input stitch of microphone assembly can be connected to serial port frame synchronization stitch on main frame and the serial port of main frame for example runs on non-frame (unframed) pattern.Data flow in data buffer is from the data from this microphone assembly, and the coding of software routines or main frame is written as the data that make from different microphone assemblies and is treated separately.By suitable selection CLK phase place, the parts of selecting PDM data to rise.This is how PDM interface to be set to adapt to an example of host process, and alternate manner is well known in the art.

At present, proposed to provide in conjunction with main frame by the digital audio interface type such as SLIMbus or I2S+I2C interface standard the scheme of this control data capability.These standards allow mutual parts and host part control data communication.But they trend towards very complicated.Much mobile and static equipment manufacturer has participated in working group and has developed SLIMbus interface, and this interface is supported a lot of digital audio parts simultaneously, and carries multiple digital audio data streams according to different sample rates and bit width.Clock frequency is very high, that is, 28MHz, provides the high ability that enables to control multiple microphone assemblies and multiple (for example 24) loudspeaker assembly, but cost is the handoff loss increasing.

Exceed two acoustic components to main frame interpolation and need to use more connection stitch, it is contrary with the trend toward miniaturization of microphone or speaker element self.Thereby a lot of industrial producers and subcontractor are not always brought to new more complicated interface standard, and still apply PDM interface for acoustic component.Therefore, in digital audio field, need the alternative of SLIMbus and I2S+I2C interface, the miniaturization that it not only provides communication alternative and considers acoustic component.

Summary of the invention

Below, by about the present invention to describe the digital microphone wind part such as microphone element in conjunction with the mode of electronic circuit.But be clear that, the present invention also can be applicable to other field, in these fields, utilize audio frequency or other transducer input and output system, can apply electronic circuit or the parts of intercommunication mutually of these types, such as being applied to digital loudspeaker, digit receiver or earphone, amplifier, also such as integrated with speaker element or parts and main frame etc.

Term " acoustic component " is defined as at least one electronic circuit and at least one audio components that comprise such as Fundamental Digital Circuit in this article.Term " parts " is not limited to only comprise and is integrally arranged on a device in device, and comprises the parts of the system of being integrated into.It is only microphone element or speaker element that term " audio components " is not limited to.Audio components can also comprise assembly.

In execution mode, provide for from least one audio components flow transmission PDM data or to the electronic circuit of at least one audio components flow transmission PDM data.

Described electronic circuit can comprise: VDD connector, for receiving VDD electromotive force, such as electrical source voltage; GND connector, for receiving the electromotive force lower than described VDD electromotive force on numerical value; CLK connector, for receiving the clock signal with high part and lower part.It at least comprises: DATA connector, for to or transmit described PDM data from main frame and/or another this electronic circuit; And L/R connector, for receiving DC electromotive force, whether this DC electromotive force is specified and is roughly synchronously communicated by letter with described high part or the described lower part of described clock signal.Term " roughly synchronously " has reflected the following fact,, depends on the whole the response time of audio components and the system of concern that is, can allow slightly to postpone or overlapping, and wherein electronic circuit is employed.Preferably synchronous communication, but, alternatively or additionally, asynchronous communication is possible and can be in suitably situation application.

Described electronic circuit also comprises I/O circuit, and this I/O circuit is configured to transmit control data via described L/R connector.

Advantage is, electronic circuit of the present invention then can to acoustic component provide with complexity the identical communication capacity of the many interface standard SLIMbus communication capacity that can provide.In addition, electronic circuit of the present invention is followed present PDM interface standard and is changed, and this quantity of connector stitch that microphone element is needed is constant.Thereby low pin number allows electronic circuit can be applicable to and be conducive to use undersized audio components, this undersized audio components provides undersized acoustic component, such as MEMS microphone assembly.Therefore, electronic circuit of the present invention provides for the possibility of adaptive (, parts are back compatibles) acoustic component backward by comprise electronic circuit according to the present invention at PDM interface.

Thereby provide a kind of electronic circuit, it has realized PDM and the data communication interface of the irrealizable combination for acoustic component so far, it provides control data on the first stitch (being L/R connector stitch), and for example, provides stream audio data being different from another second stitch of described the first stitch (DATA connector stitch).

The stitch of necessary relatively low quantity thereby consistent with PDM interface, that is, five, and connector stitch can use substantially, provides/receive identical content.Than for example SLIMbus interface, this is the particular advantages according to electronic circuit of the present invention.As the more complicated solution that sends out another audio format instead of PDM form, not only implement more expensively, and require the more digital logic component in acoustic component and main frame.Identify each specific microphone assembly with an extra stitch.SLIMbus interface provides stream audio data and controls data on same stitch, and in fact make this interface standard in fact be unsuitable for realizing, because this area still relies on general available printed circuit (such as card or chip) and in general available printed circuit or realize PDM standard in components interior.

This electronic circuit is also realized development (controlling such as gain) and the exchanges data (setting such as pattern) of the possibility of communicating by letter of main frame and acoustic component.

By the present invention, realize and used electronic circuit according to the present invention to make two or more audio components or parts also with correlation communication, to transmit for example interchange of data, control each other or mutually, for example, master/slave by limiting, or by another acoustic component is considered as to main frame.Therefore be apparent that, the available known parts that PDM interface is provided are audio content transmission completely and can not be used for transmitting control data between microphone assembly and other microphone assembly and/or main frames at present.

Utilize the present invention, due to the fact that AC level and DC level have separated on different stitch, realized surprisingly electronic circuit of the present invention and can carry out the transmission of this control data.

Known technology makes available, and wherein other stitch outside the L/R stitch of PDM interface is adjusted for controlling data.In the first trial, by superposing control data in streaming digital PDM data, send this binary digital control data with DATA stitch.In the second trial, by modulation CLK signal (modulating according to the control data that sending), control data are sent.Certainly, shortcoming is that these trials are incompatible with PDM standard, thereby not back compatible.In addition, they require to add other Analogical Electronics on acoustic component with separation of C LK and control data, for example clock recovery circuitry, and this trends towards making the physical size on plate relatively large generally.And in this scheme, only can send data to device from main frame.Thereby, according to these two trials, can not carry out the digital communication between device or from device to main frame.

The scope of knowing with regard to applicant in acoustic component field, does not propose to separate on the application's different stitch in bus the inventive method of DC and AC level before, and this may be because above-mentioned problem and scheme not be realized before this.

For transmitting digital control data, selecting L/R stitch is not apparent selection, this is because this selector stitch is considered to be applicable to special purposes conventionally, for select the change modulation of the switching of (or low to high) phase place from high to low by having two modes of operation, on DATA passage.

Electronic circuit of the present invention has met the real needs on market veritably, as mentioned above, this is because audio frequency apparatus manufacturer only can select in the past between following option: stitch a) with low quantity connects and not supported data communication, result is the more complicated communication hindering between acoustic component and main frame, or the stitch that b) has high quantity at production period connects, supported data communication, it is not compatible with the trend of the miniaturization of acoustic component, or does not consider to use popular PDM interface in industry.

In the execution mode of described electronic circuit, described I/O circuit is configured to transmit control data by sending and/or receive control data.In the time sending control data, this electronic circuit is also applicable to as host service function, controls or notify other parts, such as another main frame, or according to another electronic circuit of the present invention, or another digital unit.In the time receiving, this electronic circuit can be by from external control, such as by main frame and/or other electronic circuit control.

In the execution mode of described electronic circuit, described I/O circuit comprises I/O unit, and this I/O unit comprises the logic element for realizing the transmission of controlling data.The citation form of these logic elements can be logical block, such as OR, AND, NOR, NAND door and combination thereof.But, drive circuit can be provided in addition or alternatively.Can solve so simple communication task, shake hands such as providing, mistake processing, digital signal reception and sending function.

In the execution mode of described electronic circuit, described I/O unit comprises processor.Therefore more senior processing to data and data transmission can be provided, for example, use the logic element of flush bonding processor or other type.

In the execution mode of described electronic circuit, this electronic circuit is included in ASIC or comprises ASIC.ASIC is used to special purpose, and can provide according to suitable less physical size, suitable performance and suitable location with respect to applicable audio components.Develop the various chips design alternative for electronic circuit is provided, comprised special integrated electronic circuit (ASIC); Application Specific Standard Product (ASSP); Or structured ASIC.

In the execution mode of described electronic circuit, this electronic circuit also comprises random number generator.This random number generator can be for enumerating processing, enumerates and process for identifying to main frame or other this acoustic component comprising according to each acoustic component of electronic circuit of the present invention.Preferably, on this tandom number generator, available digital size is to select according to the maximum quantity of the circuit of estimating for each main frame.Therefore, the sum of the address providing according to the quantity of the device that will comprise in the electronic installation that will build is provided maker address space, and for example, random generator can be 16 makers.Therefore, during enumerating processing, for example, even if (there is a large amount of electronic circuits, exceed two), such as in electronic installation (for example, on printed circuit board (PCB)) there are eight circuit, each electronic circuit provides the probability of identical id number also very low at least one other electronic circuit.

In another execution mode of this electronic circuit, described random number generator is provided by the output that is arranged on the simulation sigma-delta modulator in described electronic circuit.The random number generator of other type known in the art and also can adopting.Providing random number with sigma-delta modulator or pseudo-random generator is advantage, because these elements will provide certainly, this has reduced size and the sum of the electronic component needing in electronic circuit, and this is advantage especially when the physical size of audio components little (such as MEMS element) for example.

It is to use according to comprehensive mode at this that term random is counted maker " number ", and is not intended to only be limited to integer, but can also comprise letter, symbol, machine code etc.

In another embodiment, described random number generator is pseudo noise maker, and wherein, the initial condition of described pseudo noise maker (also referred to as seed) is controlled by analogue noise source.This guarantees pseudo random sequence uncorrelated (uncorrelated), for example, and the acoustic component from an acoustic component to similar type.Like this, the id number producing from any two electronic circuits will have very high probability difference.Can be favourable based on analogue noise source, this be because this is conducive to guarantee the incoherent random process from an acoustic component to any other similar acoustic component.According to applicant's experience, comprise that similarly the like of " at random " number maker provides coincidently similar random number result in the statistics of being everlasting.The example with the parts in analogue noise source or the parts in analogue noise source is resistor and semiconductor device, for example, bipolar transistor, CMOS transistor, diode, variable capacitance diode etc., for example, provide or provide therein in acoustic component outside.Can also comprise the DC/AC element as mentioned below.

In the execution mode of described electronic circuit, described control data comprise at least one id number, and this at least one id number comprises fixing and/or random id number.Thereby this electronic circuit can be for the audio frequency apparatus of mark electronic circuit self and its outfit.Fixing id number can for example provide during manufacture, or can be assigned to device from main frame during use.

In the execution mode of described electronic circuit, this electronic circuit comprises: memory, the random id number that this memory is configured at least described fixing id number of storage and/or provides from described random number generator.Thereby for the electronic circuit of paying close attention to, specific or random id number can be stored in this memory.Can alternatively maybe can also store out of Memory, for example, about version, other acoustic component id number or the total data relevant with realizing communication between acoustic component and main frame generally, such as gain setting, filter coefficient, about the data of microphone/speaker or parameter (such as manufacturer's title, calibration mode sensitivity, date of manufacture, power consumption etc.).

In the execution mode of described electronic circuit, this electronic circuit also comprises: change-over circuit, it is for converting analog signal to from PDM data flow, or converts PDM data flow to from analog signal.Therefore, this circuit can be applicable to respectively microphone or loud speaker.In the execution mode of described electronic circuit, described change-over circuit is configured to A/D conversion (input is simulation, for example, for microphone element) or D/A conversion (input is numeral, for example, for speaker element).

In the execution mode of described electronic circuit, described I/O circuit is configured for the intercommunication mutually realizing between described electronic circuit and at least one other this electronic circuit.Thereby, can realize now the combination of two or more electronic circuits, such as set or the group of two electronic circuits, be used for holding two or more acoustic components or element, they are for example subject to gain control mutually or have two set of an identical id number or id number, and this has reduced the burden of the set to main frame adjustment member.May there is the multiple mode of enumerating, vide infra.

In one aspect of the method, provide for from least one audio components flow transmission PDM data or to the digital audio parts of at least one audio components flow transmission PDM data, this acoustic component comprises: according at least one electronic circuit of the present invention, it is configured to be connected at least one main frame and/or at least one other acoustic component; And at least one audio components, it is connected to described at least one electronic circuit.As mentioned above, the current PDM interface of this digital audio parts backward compatibility.Thereby making it possible to provides and the interface of current PDM interface backward compatibility by described acoustic component, this is because it has an equal number connection stitch.Thereby this acoustic component provides the communication capacity between microphone/speaker/amplifier unit and host-processor and/or between microphone/speaker/amplifier unit.In fact this met the real needs on market.

According to the execution mode of described acoustic component, described at least one electronic circuit is also configured for that transmission will be converted into the audio signal of PDM data flow and/or for receiving the PDM data flow that will be converted into audio signal.Therefore, can processing control signals such as the identical of improved ASIC or the electronic circuit that connects and the voiceband data signal of digital PDM signal form the two.

According to the execution mode of described acoustic component, described at least one audio components comprise speaker element, microphone element, amplifier element, processor elements (such as main frame) with and combination in any at least one.Thereby, at this moment, suppose that the development in future of at present available element and audio components is available.Thereby also expection can be proved to be the applicable common mode acoustic component that includes one or more audio components.

According to the execution mode of described acoustic component, this audio components comprises MEMS device or ECM device.Therefore, can realize miniaturization or relative little device or the acoustic component of physical size, that is, there is the rank that is less than the surface area from 1mm to 3mm.Therefore the PDM interface that, has a limited quantity stitch or a leg (five altogether) is applicable to this acoustic component better.

According to the execution mode of described acoustic component, the L/R connector of described acoustic component can be connected to VDD or GND or can be kept unsteady via at least one DC element, and the L/R connector of described acoustic component also can be connected to the control FPDP of main frame and/or be connected to the L/R connector of at least one other this acoustic component and/or be connected to the L/R connector of at least one electronic circuit via at least one AC element.This electronic structure makes single audio components to control data communication with main frame/acoustic component/electronic circuit, because be applicable to the concrete application of acoustic component.

According to execution mode, provide according to the set of at least two acoustic components of the present invention or combination, it comprises the first acoustic component and the second acoustic component, wherein, the L/R connector of described the first acoustic component can be connected to VDD via at least one DC element, the L/R connector of described the second acoustic component can be connected to GND via at least one the 2nd DC element, the L/R connector piece of the L/R connector of described the first acoustic component and described the second acoustic component is connected to each other via at least one AC element, and the L/R connector of described the first acoustic component and the L/R connector of described the second acoustic component also can be connected to the control FPDP of described main frame or the 3rd acoustic component or electronic circuit.

Advantage comprises the following fact, for ease of assembling onboard, each L/R of each acoustic component can be connected the production period of PCB of two or more combinations of acoustic component in advance and connects comprising.Two or more acoustic components can provide lumpedly or individually, and wherein lump provides and further makes assembling process simple, and because two L/R connectors are connected to each other, make to provide separately to become possible and easy.Term " parts " is not limited to single housing at this, and be applied to the single acoustic component in the housing that comprises for example two or more audio components (such as two similar or different this elements or), or be applied to the PCB that comprises two or more element integrated with other electronic device.

According to execution mode, provide a large amount of this set of two acoustic components.By audio components or acoustic component are connected over the ground with two one, suppose the setting that uses PDM interface, the each of two parts can be identified separately, thereby only by according to two one group provide multiple acoustic components of the present invention and with DC/AC elements combination, can obtain the acoustic component of the required quantity of application-specific.

According to the execution mode of described acoustic component, an acoustic component or at least two acoustic components are provided, also comprise integrated main frame, such as application processor or CODEC.Thereby can obtain integrated parts, and the audio interface of wherein one or two audio components is provided with integrated processor, and it then can be connected to Fundamental Digital Circuit arbitrarily and able to programme for application-specific that wherein acoustic component is included.In the time that production has the electronic equipment of multiple acoustic components, by selecting the stitch of correct number, can realize and be easy to adjust and data communication.

According to the execution mode of described acoustic component, described acoustic component is configured to be connected to main frame, and described main frame is specifically programmed as transmitting described control data.According to the alternative embodiment of described acoustic component, described acoustic component is configured to be connected to main frame, and described main frame is not specifically programmed as transmitting described control data.Therefore whether the user of acoustic component can select to wish main frame is programmed for and makes main frame to receive/to send from/to the L/R stitch of each and/or two acoustic components to control data.Thereby the conventional main frame not even being specifically programmed also can use with acoustic component according to the present invention is collaborative.This provides the very useful creationary interface cooperating with the main frame of traditional not dedicated programmed and/or existing audio devices and electronic equipment, and this fact has been expanded the scope that acoustic component is applicable to existed system/equipment backward.For example, if main frame is not specifically programmed, each acoustic component sends the unique ID number code of oneself.Main frame will be in response to action, and any answer is not provided.Then, acoustic component can be configured to flow transmission PDM data, for example immediately, or for example default intercept circulation after, for example circulation of the clock from 32 to 100 at most.

In another aspect of the present invention, a kind of interface system is provided, it is for from least one audio components flow transmission PDM data or at least one audio components flow transmission PDM data, this system comprises according at least one acoustic component of the present invention and comprises main frame or another acoustic component or the electronic circuit of controlling FPDP, wherein be connected to VDD or GND for the L/R connector of at least one acoustic component via at least one DC element, or be kept unsteady, and the L/R connector of at least one acoustic component is connected to the control FPDP of main frame or another acoustic component or electronic circuit via at least one AC element.

In another embodiment, this interface system comprises at least two audio components in acoustic component separately, described acoustic component is the first acoustic component and the second acoustic component, wherein, the L/R connector of described the first acoustic component is connected to VDD via at least one DC element, the L/R connector of described the second acoustic component is connected to GND via at least one the 2nd DC element, the L/R connector of described the first acoustic component and the L/R connector of described the second acoustic component are connected to each other via at least one AC element, and the L/R connector of described the first acoustic component and the L/R connector of described the second acoustic component are also connected to the control FPDP of described main frame or another acoustic component or electronic circuit.

In another embodiment, provide a kind of interface system, this interface system comprises four audio components in acoustic component separately, and described acoustic component is the first acoustic component, the second acoustic component, the 3rd acoustic component and the 4th acoustic component; And main frame, it comprises control FPDP, wherein, the L/R connector of described the first acoustic component and described the 3rd acoustic component is connected to VDD jointly via at least one DC element, the L/R connector of described the second acoustic component and described the 4th acoustic component is connected to the common L/R connector of described the first acoustic component and described the 3rd acoustic component jointly via at least one AC element, and the common L/R connector of described the second acoustic component and described the 4th acoustic component is connected to the control FPDP of described main frame or another acoustic component or electronic circuit.

Alternatively, a kind of interface system is provided, this interface system comprises: the first acoustic component, the second acoustic component, at least four audio components in the 3rd acoustic component and the 4th acoustic component, wherein, the L/R connector of described the second acoustic component and described the 4th acoustic component is connected to GND jointly via at least one DC element, the L/R connector of described the first acoustic component and described the 3rd acoustic component is connected to the common L/R connector of described the second acoustic component and described the 4th acoustic component jointly via at least one AC element, and the common L/R connector of described the first acoustic component and described the 3rd acoustic component is connected to the control FPDP of described main frame or another acoustic component or electronic circuit.

Thereby, a kind of simple and general bus is provided, the electric power that its proportion of utilization is as low in SLIMbus interface, because not needing extra stitch with PDM interface backward compatibility, except each acoustic component adding, can provide with only two other for example external components and a digital I/O, and realize and be easy to enumerate processing.In addition, be applicable to arbitrarily a quantity acoustic component and can be attached to the main frame that uses system of the present invention.

Between the reactance (being resistance value and the frequency content of capacitance or inductance value, DC element) of AC element, compromise and be not simple task, for example, if extract electric current from communication interface.In the time using L/R connector that this control data pins is provided, realized L/R not positive reaction of stitch and be directly attached to respectively GND or VDD, between there is no resistive/reactive components, this is because this is tending towards the stitch short circuit of communicating by letter by PDM.Draw on this/pull down resistor element can provide from stitch outside, or can add or alternatively provide in inside, for example, and the stitch inside in electronic circuit self.

Be intended that via the DC element such as resistor L/R is connected to VDD or GND, and via the AC element such as capacitor, the I/O of L/R connector, main frame is couple to together.Result is only to have added several extra external components.In addition, realized and enumerated processing, it realizes the physical connection of mark component uniquely without any additional stitch in the situation that.

In addition, can easily and simply add more single or paired microphone or loud speaker or amplifier or host part or element, and without add other extra electronic device (such as capacitor or resistor etc.) to interface system.

An advantage is that audio frequency apparatus can be used as autonomous system, does not need main frame to intercom mutually.

In another execution mode of described interface system, described main frame is not specifically programmed or is not specifically programmed as transmitting described control data.Therefore, acoustic component enters PDM backward compatible mode.

In another execution mode of described interface system, described at least one DC element and/or at least one AC element are cut-off filters.Thereby, comprise AC and DC element, such as, for example, the cut-off filter parameter of C, (L), R and power consumption can suitably be selected the control data transmission (send or receive) that provides stable.

In another embodiment, this system also comprises biasing control or piece.Particularly, in the time of for example two similar or different acoustic components of service or element, this system can be configured on L/R stitch provides I/O data controlling on data wire, and L/R stitch is configured for the available I/O voltage standard for Digital Logic electronic circuit (such as console controller) at present and cooperates.

In one aspect of the method, provide for from least one audio components flow transmission PDM data or to the method for at least one audio components flow transmission PDM data, the method comprises: provide according at least one electronic circuit of the present invention, described method comprises described at least one electronic circuit is connected to described at least one audio components thereby at least one digital audio parts is provided, the VDD connector that receives VDD electromotive force is provided, provide and receive the GND connector of numerical value lower than the electromotive force of described VDD electromotive force, the CLK connector that receives the clock signal with high part and lower part is provided, provide to or from described at least one audio components or to or transmit the DATA connector of described PDM data from main frame and/or another this electronic circuit, provide to receive and whether specify the L/R connector that roughly synchronously transmits DC electromotive force with the described high part of described clock signal or described lower part, and also provide the I/O circuit that transmits described control data via described L/R connector.

In another execution mode of the method, the method also comprises: the L/R connector of described at least one electronic circuit or digital audio parts is connected to and comprises main frame or another acoustic component or the electronic circuit of controlling FPDP.

In another execution mode of the method, the method also comprises: the L/R connector of described at least one electronic circuit or described at least one acoustic component be connected to VDD or GND via at least one DC element or kept floating, and via at least one AC element, described at least one electronic circuit or described at least one acoustic component L/R connector being connected to the control FPDP of main frame or another acoustic component or another electronic circuit.

In another execution mode of the method, the method also comprises: the first acoustic component and at least two acoustic components of the second acoustic component are provided, the L/R connector of described the first acoustic component is connected to VDD via at least one DC element, the L/R connector of described the second acoustic component is connected to GND via at least one the 2nd DC element, the L/R connector of described the first acoustic component is connected to each other via at least one AC element, and the L/R connector of the L/R connector of described the first acoustic component or described the second acoustic component is connected to the control FPDP of described main frame or another acoustic component or electronic circuit.

In the execution mode of the method, the method comprises cut-off filtering.In the execution mode of the method, the method comprises the biasing control of described control data.

In another execution mode of the method, each is controlled to data pins and carry out medium access control, for example 1-continues carrier sense multichannel sensing (CSMA), it is a kind of probabilistic medium access control (MAC) agreement, in this agreement, before transmitting on shared transmission medium (such as electrical bus), whether for example individual node (bit) checking there is not other Business Stream.Because it is simple, so can be favourable.It is favourable carrying out CSMS, to guarantee that multiple unit do not send at the same time.

In another execution mode of the method, also described control data are carried out to error checking.Thereby, increase such as the receiving element of main frame and will therefore finally receive the probability of correct data.

In another execution mode of the method, generate random and/or fixing id number according to electronic circuit of the present invention, and this id number is sent to main frame or another acoustic component or another electronic circuit via L/R connector.In favourable execution mode of the present invention, this is to carry out before at least one the PDM audio signal operation after powering up and in described audio components or parts.Advantage is between the starting period of electronic installation that comprises acoustic component, promptly (for example, approximately after several milliseconds) and correctly the parts of notified which kind of type are ready and available of main frame or other processor (for example central processing unit).

In another execution mode of the method, the in the situation that of address conflict, this main frame repeats this processing until be provided the special one number of acoustic component with all audio frequency parts of described main-machine communication.This also can carry out by acoustic component self or by another acoustic component and/or electronic circuit.In another execution mode of the method, the special one number of each acoustic component is stored in the memory of described electronic circuit.

In another execution mode of the method, all audio frequency parts are by the main frame or acoustic component or the synchronously clock control of electronic circuit that are adjusted to carry out clock control.This becomes easily the signal processing of carrying out subsequently, and has reduced and processed the voice data that receives or send to acoustic component from acoustic component and the quantity that controls the needed processing unit of data.

In another execution mode of the method, to each set of each independent acoustic component and/or acoustic component control that gains.This has realized automatic electric-level control (ALC) and simulation mixes, for example carried out for multiple acoustic components by a main frame, or carry out (in the time that each acoustic component has carried out mark to this main frame respectively, being possible) by a main frame for single acoustic component.

Brief description of the drawings

In order more completely to understand the disclosure, with reference to following detailed description and appended signal accompanying drawing, wherein, identical Reference numeral represents same parts:

Figure 1A illustrates according to the end view of the acoustic component of prior art, and this acoustic component comprises electronic circuit and MEMS microphone element,

Figure 1B illustrates the microphone assembly according to prior art, and this microphone assembly comprises MEMS microphone element and electronic circuit, and is configured to use five PDM interface pin DATA, L/R, CLK, VDD and GND to be connected to main frame,

Fig. 1 C is illustrated according to the data wire of clock control in the PDM stream of prior art,

Fig. 2 illustrates according to the figure of the exemplary setting of the different parts in the electronic equipment of prior art,

Fig. 3 illustrates according to the physical layer of the acoustic component for flow transmission PDM data of embodiment of the present invention,

Fig. 4 illustrates that wherein this system also comprises the BIAS piece not enabling according to the physical layer of the acoustic component for flow transmission PDM data of embodiment of the present invention,

Fig. 5 illustrates the example of the BIAS piece that the realization remittance shown in Fig. 4 and source enable,

Fig. 6 illustrates that wherein these parts also comprise the BIAS piece enabling according to the physical layer of the interface system for flow transmission PDM data of embodiment of the present invention,

Fig. 7 illustrates the figure as the control data voltage of the function of time, and it has described the stage that powers up, the processing stage of enumerating and the ready or operational phase of interface system,

Fig. 8 A illustrates the microphone assembly according to embodiment of the present invention, and it comprises the electronic circuit that is configured to be connected to main frame or another acoustic component according to embodiment of the present invention,

Fig. 8 B illustrates the loudspeaker assembly according to embodiment of the present invention, and it is configured to be connected to main frame or another acoustic component,

Fig. 9 illustrates four microphone assemblies altogether according to embodiment of the present invention, and they can be connected to according to the main frame in the interface system of embodiment of the present invention, and

Figure 10 illustrate there is CLK layer, the frame setting of the data link layer of DATA bit-level and coded-bit layer.

It will be understood by those skilled in the art that key element in accompanying drawing is in order to simplify and object and illustrating clearly.In addition, should also be understood that and can describe or describe specific action and/or step according to specific order of occurrence, but this area skill personnel will understand the actual this specificity about order that do not require.

Embodiment

Although the disclosure is easy to carry out various modifications and variations, by example, specific implementations is shown in the accompanying drawings, and these execution modes will be described at this in detail.But, it should be understood that the disclosure is not intended to the present invention to be limited to described concrete form, on the contrary, the invention is intended to cover and fall into whole amendments in the spirit and scope of the present invention defined by the appended claims, replace and be equal to.

As mentioned above, SLIMbus is the interface scheme more complicated than PDM interface, need to be for the right data pins of each microphone that is connected to this bus and for identifying an extra stitch of each particular microphone.PDM interface (, the current pulse density modulated interface for voice applications) is not supported this microphone communication.

Numeral PDM bit stream is encoded from analog signal by the processing of for example delta-sigma modulation.This processing quantizer that produces 1 or 0 according to the amplitude of analog signal.1 or 0 corresponding to full-scale (full scale) signal.

Belong to which microphone assembly in order to make processor or main frame understand bit alternately, the clock of microphone assembly (be often serial port operation clock 1/2nd) be connected to the serial port frame synchronization stitch of main frame, and serial port runs on non-frame pattern.Serial port starts to receive data from the first rising edge of the clock of microphone assembly, and this selects stitch to be shorted to the data of the microphone assembly of VDD by being from its L/R.This means the rising edge driving data of this microphone assembly at clock.Therefore,, under the whole circumstances, the data flow in data buffer is from the data from this microphone assembly, and software routines is written as the data that make from different microphone assemblies and is treated separately.

Referring to Figure 1A, microphone assembly comprises the acoustic component 110 such as MEMS microphone element and electronic circuit, wherein illustrate MEMS microphone element with physical side, bottom outlet microphone 110 is wherein set in the small-size chips that comprises circuit, is integrated in PCB above or is otherwise arranged on PCB above and transmit the voice data of PDM style with the acoustic component 110 that makes to combine.Because size is limited, the connector of limited quantity or stitch can be applicable to this acoustic component.MEMS microphone element comprises substrate and is arranged in suprabasil first case as membrane configuration 102.The second structure 118 is arranged in the first structure and the second structure is configured to define the first chamber and has at least one sidewall that is attached to the first structure.At least one MEMS100 is arranged in described chamber and through described sidewall and forms the first acoustics port one 20.The first acoustics port one 20 provides and allows acoustic energy to enter MEMS audio components with by the passage of voicefrequency circuit processing.MEMS microphone assembly 110 can comprise single MEMS element or two MEMS element and comprise electronic circuit 114.MEMS microphone assembly or its assembly are often called as " MEMS " in daily term, but in this case avoid confusion and will be called MEMS microphone assembly.

Figure 1B illustrates according to the acoustic component of the prior art of application PDM interface, this PDM interface (comprises the electronic circuit of MEMS microphone element and ASIC form, altogether comprise five stitch): VDD, DATA, CLK, L/R and GND stitch, and the digital PDM signal that comprises audio frequency or sound-content is provided on DATA stitch.

In Fig. 1 C, as example, PDM data and CLK after the modulation of prior art MEMS microphone assembly are shown, this MEMS microphone assembly will be connected to main frame or processor by the serial port on main frame or processor.This microphone can the logic level based on L/R stitch drive PDM data at rising edge or the trailing edge of clock.By identical clock in 1 to 4MHz scope is provided to microphone assembly and serial port and receives PDM data to processor and keep L/R stitch to be attached to GND or VDD from serial port simultaneously, carry out the docking of single microphone assembly.For two this microphone assemblies are connected to single serial port data wire, the L/R stitch of a microphone assembly can be by direct ground connection.The L/R stitch of another microphone assembly is directly attached to VDD.This guaranteed microphone assembly in the opposite edge of clock along driving data.In order to make serial port receive data from two microphone assemblies, can carry out clock control to microphone assembly according to 1/2nd of the speed of the clock in serial port operation.Microphone assembly carrys out audio signal modulation with respect to the clock that is fed to it.For dual microphone unit interface, the data of reception buffer inside will by bit-by-bit interweave.This means that each alternate bit belongs to same microphone assembly.The timing of the data that driven with respect to clock by microphone assembly in prior art is L/R stitch according to PDM interface pin purposes and based on microphone assembly.If L/R stitch is attached to GND stitch, driving data on the rising edge of clock.If L/R stitch is attached to VDD stitch, driving data on the trailing edge of clock.

In Fig. 2, show electronic audio device, for example PDA, it comprises multiple audio components, such as numeral or analog speakers, earphone and microphone.

According to providing in the system of the present invention of alternative interface system described below, can advantageously assemble or upgrade described equipment with one or more electronic circuit according to the present invention, auxiliary audio frequency parts according to the present invention.

Provide application from least one audio components flow transmission PDM data or to the electronic circuit of at least one audio components flow transmission PDM data.Described electronic circuit comprises: for receiving the mains connection of VDD electromotive force, referred to here as VDD connector; For receiving the earth connection of numerical value lower than the electromotive force of described VDD electromotive force, referred to here as GND connector; For receiving the clock connector of the clock signal with at least high part and lower part, referred to here as CLK connector; For to or transmit the DATA connector of the described voice data of PDM form from main frame and/or another this electronic circuit; And for receiving the L/R connector of the DC electromotive force whether appointment roughly synchronously transmit with described high part or the described lower part of described clock signal.Described electronic circuit also comprises I/O circuit, and it is configured to transmit control data via described L/R connector.Described control data can be numerical datas, it is suitable for making main frame or another parts can resolve these data, for example, such as the digital id number of identification audio parts, and/or can be the logical signal for drawing or push away Host Command, and/or can be to be considered to as known in the art the digital information of communicating by letter with main frame or other parts in other side improvement.

For comprising according at least one electronic circuit of the present invention from least one acoustic component flow transmission PDM data or to the digital audio parts of at least one acoustic component flow transmission PDM, this at least one electronic circuit is configured to be connected to main frame and/or at least one other acoustic component, and wherein, described at least one audio components is connected to described electronic circuit to send the PDM data flow that will convert the audio signal of PDM data flow to and/or will convert audio signal with reception to.

For comprising according at least one acoustic component of the present invention from least one acoustic component flow transmission PDM data or to the interface system of at least one acoustic component flow transmission PDM, also comprise main frame, this main frame comprises control FPDP, wherein, the L/R connector of at least one acoustic component is connected to VDD or GND via at least one DC element, and the L/R connector of the first acoustic component is connected to the control FPDP of main frame via at least one AC element.

Therefore, L/R stitch is connected to cut-off filter in one embodiment, with as Fig. 1 visible burning voltage electromotive force Vo.This interface system is characterised in that physical layer and data link layer, as discussed below.

Figure 3 illustrates the physical layer of execution mode, wherein, by via outside DC element (resistor R is called as the pullup resistor with predetermined resistance), L/R stitch being connected to the electromotive force VDD higher than GND, L/R stitch is drawn high to Vo.Alternatively, L/R stitch can keep floating or being connected to electromotive force GND and being dragged down by the resistor R via identical or different value (thereby being called pull-down-resistor).From the circuit diagram of Fig. 3, L/R connector is directly attached to GND or VDD is disadvantageous, because this will cause the short circuit of this stitch, that is, in fact by communication port short circuit.

In Fig. 3, the microphone element I/O being drawn high is connected to the COM port of main frame (not shown) by AC element.AC element is capacitive element,, has the external capacitor C of predetermined capacitance value and/or inductance value that is.Thereby, for sending or receive the DC level of controlling the communication interface of data the sequence of transmission is superimposed upon L/R stitch place.

Thereby Fig. 3 shows the cut-off filter with time constant and cut-off frequency.For determine or select reactance value (, capacitor C and resistance (being resistance value R)), need to carry out some considerations for system: a) electrostatic current in the time moving L/R stitch to Vo by VDD or GND or other electromotive force consumes A, b) for system select for stablizing the start-up time of L/R value,, start-up time after powering up, and c) obtain according to for system and/or for to or bus application that may or expect from the communication COM of main frame and the cut-off filter frequency of communication speed.

Electric capacity c shown in Fig. 3 is often the instruction (for example, in the time arranging onboard) of the parasitic capacitance associated with this Fundamental Digital Circuit, and this c conventionally can be from approximately 10 magnitudes to about 500pF.

Can be the current drain lower than the magnitude of 100 milliamperes for the representative value that this cut-off filter is provided, be preferably lower than 50 milliamperes, most preferably about 5 to 10 milliamperes.Can be according to being used for selecting start-up time, for example, in order to coordinate start-up time with the start-up time corresponding to being applied to main frame, for example make first signal from acoustic component before main frame powers up, simultaneously or arrive afterwards main frame.For changing the start-up time of stablizing L/R potential value, but can be in the magnitude that is often less than 100 milliseconds.The selected frequency content obtaining of this bus can be in the magnitude of about 100kHz.

The example value of cut-off filter: corresponding to the value of A, can be according to following selection start-up time, C and R, so that the cut-off filter shown in Fig. 3 to be provided: 10 milliamperes of current drains, start-up time are from approximately 5 to 10 milliseconds.Not high by C and the stable cut-off filter calibration of R ground, it allows bus communication, therefore uses cut-off at about 10kHz as example.This for example obtain 100 kilohms on draw/pull-down-resistor R value, if the peak of the signal value of bus equals VDD to cutting edge of a knife or a sword value, obtain corresponding to the about maximum consumption of power of VDD/2.If therefore VDD=1.8V, current drain is 9 milliamperes.If selected less swinging of signal, obtain lower current drain.If cut-off frequency is chosen as 1kHz, this obtains capacitance 1.6nF.Filter time constant will be 100kHz × 1.6nF=160 millisecond.For 1% steady state error, will be approximately 737 microseconds the stabilization time that this expression obtains, that is, stabilization time and cut-off frequency the two by low approximately two ten (decade).

As known in the art, multiple other schemes, can be applicable to float or pull L/R stitch, for example, and by other filter type and/or signal control circuit.But it can be favourable to reduce parts and device fabrication cost and still to provide the advanced data transmission between for example acoustic component and main frame that this simple and effective cut-off filter is provided simultaneously.

Because this AC coupling of filter is tending towards removing DC value and the center of COM signal VDD/2 is fixed on to VDD or GND, in the execution mode of interface system, interface system also comprises biasing control or piece, when two audio components being for example set in parts or when two independent acoustic components include an audio components, this is preferred.This is that form in order to read with standard host provides COM signal, i.e. standard digital I/O signal or full-scale signal.

Fig. 4 to Fig. 7 shows the example that for example, how can construct this biasing structure between two acoustic components (, similar acoustic component MIC1L and MIC1R).

Fig. 4 shows in its underpart from the COM signal of the MIC1L VDD/2 that how to be shifted after cut-off filter, centered by VDD instead of centered by VDD/2.Use the pullup resistor Rpu in receiving terminal, DC electromotive force is pulled to VDD at this.As shown on the top of Fig. 4, be provided with bias block VDD/2, but it is not enabled (as shown in the figure, switch S I keeps open circuit).The alternate manner that this biasing control is provided is known in the art, for example, uses pure resistive parts.

In the case, as shown in Figure 5, as shown on the top of figure, provide bias block figure key element, it comprises the element that for example bottom at figure is described.This bias block comprises the Voltage-controlled Current Source by low frequency circuit controls.Difference transducing level Gm compares the version after the low-pass filtering of VDD/2 and output, and thereby correspondingly regulation voltage is to Gm level, it will converge or source electric current.For example, available RC filter extracts the DC value of bus, C _biasand R _bias, this time constant is selected as large not affect the COM signal transmission in bus.Bias block is displaced to the ability of remittance or source electric current and can be controlled by the switch S 2 and the S3 that are inserted in respectively in Gm level between VDD and GND.For example, if bias block will be in source module, if utilize external resistor to be pulled to earth potential such as bus, switch S 2 can closure and switch S 3 can open.In the situation that converging pattern, contrary application.

During realizing this bias block by Closing Switch Si, referring to Fig. 6, illustrate in the bottom of figure in the time bias block being enabled by Closing Switch s1, thereby how to be shifted centered by about VDD/2 at the signal COM of receiving terminal.In the situation that pullup resistor adds bus to, then bias block is arranged on remittance pattern.Under reverse situation, in the situation that adding pull-down-resistor, then bias block is arranged on source module.This structure guarantees that multiple bias blocks can be coupled concurrently and not cause conflict.

How the COM signal of system (, S1 closure) from being provided with the bias block being enabled shown in Figure 7 in the bus of receiving terminal be along with the time changes.First, have the short period starting from TO, wherein acoustic component powers up.After T1, be the stage that provides L/R to select for two elements/components, in this cycle, bias block is enabled, and then at T2, enter the processing stage of enumerating, and bus is finally ready to sending/receiving COM signal or multiple COM signal after T4.According to the type of parts, main frame or PDM data content, can suitably select T1, T2, T3 and T4, and can be at about 1ms the magnitude to 1000ms, such as 100 milliseconds.

Shown in Fig. 8 A and Fig. 8 B according to exemplary audio parts of the present invention, be respectively microphone assembly 10A and loudspeaker assembly 10B.In Fig. 8 A, microphone assembly 10A comprises microphone element 12 and according to electronic circuit 14A of the present invention, provide as five of above restriction stitch connector VDD, DATA, CLK, L/R and GND stitch, and the digital PDM signal that comprises audio frequency or sound-content is provided on DATA stitch.In Fig. 8 B, loudspeaker assembly 10A comprises speaker element 16 and according to electronic circuit 14B of the present invention, provide as five of above restriction stitch connector VDD, DATA, CLK, L/R and GND stitch, and the digital PDM signal that comprises audio frequency or sound-content is provided on DATA stitch.PDM signal receives from main frame to DATA stitch at this, and contrary with Fig. 8 A, wherein PDM signal sends to main frame from DATA signal.

In Fig. 8 A, comprise the charge pump 142 being connected with the first output pin of microphone element 12, the amplifier 144A being connected with the second output pin of microphone element 12 according to electronic circuit 14A of the present invention (comprising ASIC at favourable execution mode), so that the inlet point of analog signal to be provided from microphone element 12.This electronic circuit also comprises A/D converter (such as sigma-delta modulator 146), and it is connected to amplifier 144 to spread and to be passed to the digital PDM signal of main frame (not shown) converting to from the outputting analog signal of microphone element 12 from DATA stitch.Protocol block 150 comprises memory 152 and random number generator 154 at execution mode.Piece 150 is connected to the control data on L/R stitch via I/O port, and thereby be configured for control data communication, for example, receive and/or send from main frame (not shown) or according to the control data of other acoustic component of the present invention.

In Fig. 8 B, comprise prime amplifier 144B according to electronic circuit 14B of the present invention (comprising ASIC at favourable execution mode), it is connected to carry analog signal leaving a little to speaker element 16 with the first input pin and second input pin of speaker element 16.This electronic circuit also comprises D/A converter 148, and it is connected to prime amplifier 144B to convert streaming digital PDM signal speaker element 16 and that offer loudspeaker assembly/electronic circuit by DATA stitch from main frame that goes to of input to analog signal.In Fig. 8 A, protocol block 150 comprises memory 152 and random number generator 154 at execution mode.Piece 150 is connected to the control data on L/R stitch by I/O port, and thereby be configured for control data communication, for example, receive and/or send from main frame (not shown) or according to the control data of other acoustic component of the present invention.

Figure 9 illustrates the schematic diagram of execution mode, wherein electronic circuit of the present invention and/or acoustic component are connected in acoustic component system.Fig. 9 shows system according to the embodiment of the present invention, and the combination of two set of acoustic component (, four similar digital mini microphone parts) is connected to main frame by this system for example.

Fig. 9 for example shows in the first composite set, according to the microphone assembly MIC1L of similar type of the present invention and MIC2R be combined for by the PDM data stream transmitting from all parts to the public DATA1 port on main frame (not shown).In the second composite set, according to the microphone assembly MIC3L of similar type of the present invention and MIC4R be combined for by the PDM data stream transmitting from all parts to the public DATA2 port on same or another main frame (not shown).Select according to L/R stitch, PDM data are streamed to main frame.Use public DC element R, the L/R stitch of parts MIC1L and MIC3L is pulled to respectively public the first electromotive force VDD.In addition,, in the first side (being connected to the opposition side of the first electromotive force VDD) of AC element (capacitive element C), the L/R stitch of parts MIC2R and MCI4R is pulled to respectively public the second electromotive force.In fact this provide cut-off filter structure.Provide control data by each in provided L/R stitch, this structure allows to control that data are sent individually by each acoustic component and receive (or allow to control data sent by main frame and received individually by each acoustic component) further to process by main frame.Therefore, this System Construction allows the independent data communication between main frame and each acoustic component.Should also be noted that and can add a lot of hope other acoustic component 5...N to system, as long as there is N signal data port or FPDP (DATA N) on the main frame in system or multiple main frame.In the time of assembling audio system, this correspondingly requires device fabrication business to carry out minimum attended operation, such as welding operation.And external electrical AC and DC element easily obtain on market.Alternatively or additionally, can provide this stable electromotive force other filter to varying level that pulls that provides known in the art.

In fact,, by the present invention, provide a kind of PDM interface of alternative, that is, the expansion of the PDM interface of application at present, it is realized by electronic circuit according to the present invention, wherein, L/R connector also, as communication interface, makes the current PDM interface standard of acoustic component back compatible simultaneously.Current PDM interface is by being connected to VDD by L/R or GND carrys out work.L/R connection is allowed to acoustic component and the back compatible of correlation technique PDM interface of for example microphone assembly for controlling this purposes of data.Back compatible can be understood to be illustrated in the situation of revising hardly or not revising, can cooperate together with the acoustic component non-of the present invention (, they do not send and control data on their L/R stitch) of realizing known PDM interface according to electronic circuit of the present invention or acoustic component.

Multiple acoustic components can use same protocol to communicate by letter on universal serial bus with individual host, and wherein, one or more parts and main frame are called as communication unit generally.Any two unit can carry out direct communication with point-to-point communication, and wherein, the each unit in bus has the unique address of this unit, can be assigned for example address 1...14 such as parts, and main frame is assigned address 0, wherein, address is assigned to parts during enumerating, and vide infra.Thereby, utilizing broadcast (for example, address 15 is used to indicate this), any unit can be immediately and whole other component communications.

According to the application of expecting, can be used as the microphone and the receiver element that comprise (but not exclusive) speaker element, receiver element, silicon receiver element based on MEMS, dual collector element, electret microphone element, dynamic microphones element, silicon microphone element based on MEMS, dual microphone element, combination according to other example of the audio components of a part for acoustic component of the present invention.According to the application of expecting, can be integrated electronic circuit (IC) according to electronic circuit of the present invention, the ASIC of for example any suitable type, or can comprise at least one or its combination in the selection of amplifier, capacitor, resistor, inductor or other passive component, digital 1/O port, D/A and A/D converter, logic port, programmable element etc.It should be understood that one or more audio components and one or more electronic component can be included in according in acoustic component of the present invention.Audio components and electronic circuit can be integrated in one single chip.Alternatively, audio components can or be connected to electronic circuit with alternate manner known in the art by wire or welding.

Figure 10 illustrates example and the method for the frame structure of the control data in the data link layer that how can implement electronic circuit according to the embodiment of the present invention, wherein, be provided for the mark of 8 bits of the beginning that signals frame or header, for the payload of 8 bits of address, control and data and for the CRC of 8 bits of error detection, as described herein.

Carry out line coding, because frame data will send by the capacitor in physical layer for example.Any DC signal component (low-frequency component) in frame data can be removed to avoid baseline shift.This is by using with a lower scheme, frame data to be encoded to realize: more complicated 8B/10B coding or Manchester's code.

8b/10b is line code (line code), and it is mapped to 10 bit symbols to realize DC balance and limited difference by 8 bit symbols, and still provides enough state variation to allow rational clock recovery.This difference being illustrated between the counting of 1 and 0 in the string of at least 20 bits is no more than 2, and does not exist and exceed five 1 or 0 in a line.This contributes to reduce the demand of the lower bandwidth restriction to the channel for transmission of signal.

Manchester's code (also referred to as phase code or PE) is line coding, and wherein, the coding of each data bit has at least one variation and occupies the identical time.Therefore there is no DC component, and a self clock, this means can inductance or capacitive coupling, and can be from coded data recovered clock signal.

Carrier sense multichannel sensing (CSMA) is probability medium access control (MAC) agreement, wherein, before transmitting on shared transmitting medium (such as the band of electrical bus or electromagnetic spectrum), there is not other Business Stream in node verification." carrier sense " described reflector and before attempting sending, used from the fact of feedback of receiver that carrier wave detected.That is to say, reflector attempted detecting the existence from the code signal at other station before attempting transmission.If sense carrier wave, stand in described in and initiate own transmission and wait for ongoing being transmitted before." multichannel " describes multiple facts that stand in sending and receiving on medium.The transmission of a node is used whole other stations of this medium to receive conventionally.

In the execution mode of the method according to this invention, carry out medium access control, for example, 1-continues CSMA.This is here attractive, because it is simple.It is favourable carrying out CSMS, to guarantee that unit does not send at the same time and controls data.

Multiple unit use single circuit (for example using easily existing L/R stitch) to communicate by letter together.This is favourable, because transmission can be initiated at any time in any unit in the situation that there is no total tune.In order to make thing simple, do not use such as the time division multiplexing for providing in SLIKbus standard (TDM), otherwise it also can be applicable to this.But, be conveniently but not necessarily, be not blended in single bus because control data (based on event) and voice datas (real-time streams transmission) at this.

Can carry out cyclic redundancy check (CRC) (CRC), it is error-detecting code, is designed to detect the accidental change to original calculation machine data, and is generally used for digital network and storage device, such as hard disk drive.Support the parts of CRC to calculate the binary sequence of short regular length for each data block that will send or store, be called check value or (irrelevantly) and be called CRC, and be attached to data, form code word.In the time that code word is received or read, the check value comparison that parts newly calculate by its check value and according to data block, or equivalently to whole code word execution CRC and by the residual constant comparison of the check value obtaining and expection.If check value does not mate, piece comprises error in data and this parts can carry out corrective action, again send this piece such as reading again to get or ask, otherwise tentation data inerrancy (although may contain undetected mistake in very little probability packet); This is the fundamental property of error checking.

In the execution mode of the method according to this invention, go back paired domination number according to carrying out error checking.Frame structure and the method for the control data of electronic circuit according to the embodiment of the present invention shown in Figure 10, wherein, mark or the header of 8 bits of the beginning for signaling frame are provided, for the payload of 8 bits of address, control and data and for the CRC of 8 bits of error detection.Mistake detected by the crc field that uses frame.Comprise mistake and ignore the frame that this receives and if RX carries out the described frame of error checking in the frame receiving.Receiving element senses identical signal with transmitting element, and wherein, as long as the mistake of detecting, transmitting element just will resend.Therefore, receiving element will finally receive correct data.Select else or other error checking can be carried out and carry out according to the method according to this invention in system.

All audio frequency parts in bus can be by main frame clock control simultaneously, wherein, derive transfer clock (TX) from host clock (SCK) with ratio of integers, and for example, derive receive clock (RX) from another clock (, serial clock (SCK)) with ratio of integers.Alternatively, can be from clock apparatus, another main frame or another acoustic component or electronic circuit receive clock.

Special consideration when the audio system equipment of structure supporting interface communication is to enumerate processing, enumerating in processing, each microphone assembly is provided unique address, for example, is linked to its specific physical location of (on the electronic installation that comprises this audio system) onboard.This is not only this area part for known identification process (wherein their existence of parts statement) conventionally.This is also directly involved in all parts with respect to other acoustic component on plate and with respect to the sound source accurate physical location of (such as using the people of this electronic installation).This is an advantage, because in the time being undertaken by main frame processing from the signal subsequently of the signal of each parts (such as reducing noise level or removing echo), in the time that the physical location of all parts is known (distance each other, upper or under, left or right, size and gain, particularly with respect to sound source), acceptable result is provided.

By observing class of school, can illustrate this position and enumerate processing, wherein, importantly not only each student (or parts) identifies oneself by name (id number), and each student raises one's hand (transmission id number) to make teacher's (main frame) can see where student is sitting in, his/her name is and whom he/her is and what can do in the time being called the roll, teacher's (main frame) can use or test or arrange student's (parts) according to teacher's expectation.

In order to identify accurate physical location (, the identity of all parts), main frame can make the whole parts except parts quiet.This makes main frame can identify which bar data circuit these parts are connected to and at which clock phase.This is repeated until identified the connection of whole parts.

As an alternative, each acoustic component can be by own quiet until the random time after powering up.This random time can be set by the random generator in each acoustic component.When acoustic component becomes while existing (, by starting to send PDM data), the order that main frame has just become existence acoustic component by sending in bus has been assigned particular address carrys out assigned address.

In execution mode, for example, between the starting period, according to each microphone assembly of the present invention (for example, electronic circuit on it or wherein) (for example generate random identification number, utilize random number generator, such as 16 makers), and send it to main frame via L/R connector.The in the situation that of address conflict, main frame repeats this processing until have the special one number of acoustic component with all audio frequency parts of main-machine communication.

In favourable execution mode, provide random number generator by the output of the simulation sigma-delta modulator having existed in electronic circuit.Thereby the quantity of the element in electronic circuit keeps less.In addition, have been noted that if all audio frequency parts are equipped with the random number generator of same type, they trend towards providing at least some similar parts id numbers.Thereby sigma-Delta provides random signal, it is more applicable for this application.

In the execution mode of method, provide the random generation of component address.All parts or electronic circuit comprise for example 16 random generators, and it is for generation of 16 bit address.The in the situation that of conflict, main frame restarts to enumerate processing.After all parts has obtained unique address, this address is mapped to for example address space between 1-14, by quiet whole parts and then they are enabled one by one, can determine accurate physical connection by first.Each acoustic component or electronic circuit have the unique address that is directly linked to physical connection part now.

Random generator is pseudo noise maker in execution mode, and wherein, the initial condition of pseudo-random generator is controlled by analogue noise source, and analogue noise source all DC in this way element, such as diode, transistor and/or resistor.

In alternative methods, enumerate processing and comprise for determining that acoustic component becomes the random generator existing in bus.After becoming in bus and existing, main frame assigned address is given each acoustic component, for example, and between 1-14, from minimum.

In the situation that two parts are present in bus with identical address or identical id number simultaneously, main frame will require them to repeat this processing.By quiet whole parts and then they are enabled one by one, can determine accurate physical connection by first.All parts has the unique address that is directly linked to physical connection part now.

Although the disclosure is easy to carry out various modifications and variations, by example, specific implementations is shown in the accompanying drawings, and these execution modes will be described at this in detail.But, it should be understood that the disclosure is not intended to the present invention to be limited to described concrete form, on the contrary, the present invention is intended to cover and falls into whole amendments in the spirit and scope of the present invention, replace and be equal to.

The preferred embodiment of the present invention has been described here, comprise that inventor knows for carrying out optimal mode of the present invention.It should be understood that illustrated execution mode is only exemplary, and should not be considered to limit the scope of the invention.

Claims

For from or to the electronic circuit of at least one audio components flow transmission PDM data, this electronic circuit comprises:

VDD connector, it is for receiving VDD electromotive force, such as electrical source voltage;

GND connector, it is for receiving the electromotive force of numerical value lower than described VDD electromotive force;

CLK connector, it is for receiving the clock signal with high part and lower part;

DATA connector, its for to or transmit described PDM data from main frame and/or another this electronic circuit;

L/R connector, it is for receiving DC electromotive force, described DC electromotive force whether specify with the described high part of described clock signal or described lower part basic synchronization transmit,

Wherein, described electronic circuit also comprises I/O circuit, and described I/O circuit is configured for via described L/R connector transmission control data.
2. electronic circuit according to claim 1, wherein, described I/O circuit is configured to transmit control data by sending and/or receive control data.
3. electronic circuit according to claim 1, wherein, described I/O circuit comprises I/O unit, and described I/O unit comprises logic element, and described logic element is for realizing the described transmission of controlling data.
4. electronic circuit according to claim 1, wherein, described I/O unit comprises processor.
5. electronic circuit according to claim 1, wherein, described electronic circuit is included in ASIC or comprises ASIC.
6. electronic circuit according to claim 1, described electronic circuit also comprises random number generator.
7. electronic circuit according to claim 6, wherein, digital size available on described random number generator is selected according to the maximum quantity of the circuit of estimating for each main frame.
8. electronic circuit according to claim 7, wherein, described random number generator is provided by the output of the simulation sigma-delta modulator arranging in described electronic circuit.
9. electronic circuit according to claim 8, wherein, described random number generator is pseudo noise maker, wherein, the initial condition of described pseudo noise maker is controlled by analogue noise source.
10. electronic circuit according to claim 1, wherein, described control data comprise at least one id number, described at least one id number comprises fixing id number and/or random id number.
11. electronic circuits according to claim 1, described electronic circuit also comprises memory, the random id number that described memory is configured at least described fixing id number of storage and/or provides from described random number generator.
12. electronic circuits according to claim 1, described electronic circuit also comprises change-over circuit, described change-over circuit is used for converting analog signal to from PDM data flow, or converts PDM data flow to from analog signal.
13. according to electronic circuit in any one of the preceding claims wherein, and wherein, described I/O circuit is configured for the intercommunication mutually realizing between described electronic circuit and at least one other this electronic circuit.
14. 1 kinds for from or to the digital audio parts of at least one audio components flow transmission PDM data, this acoustic component comprises:

At least one electronic circuit, it is configured for and is connected at least one main frame and/or at least one other acoustic component, and

At least one audio components, it is connected to described at least one electronic circuit.
15. acoustic components according to claim 14, wherein, described at least one electronic circuit is also configured for transmission and will converts the audio signal of PDM data flow to and/or receive the PDM data flow that will convert audio signal to.
16. acoustic components according to claim 14, wherein, described at least one audio components comprises speaker element, microphone element, amplifier element, such as at least one in processor elements and the combination in any thereof of main frame.
17. acoustic components according to claim 14, described acoustic component comprises MEMS or ECM.
18. acoustic components according to claim 14, wherein, the L/R connector of described acoustic component can be connected to VDD or GND via at least one DC element, or can keep unsteady, and the described L/R connector of described acoustic component can also be connected to the control FPDP of main frame and/or be connected to the L/R connector of at least one other this acoustic component and/or be connected to the L/R connector of at least one electronic circuit via at least one AC element.
19. acoustic components according to claim 14, described acoustic component also comprises integrated host, such as application processor or CODEC.
20. acoustic components according to claim 14, wherein, described acoustic component is configured to be attached to main frame, and described main frame is specifically programmed as transmitting described control data.
21. according to the acoustic component described in any one in claim 14 to 20, and wherein, described acoustic component is configured to be attached to main frame, and described main frame is not specifically programmed as transmitting described control data.
22. 1 kinds have the system of at least two acoustic components, and this system comprises:

The first acoustic component and the second acoustic component, and wherein,

The L/R connector of described the first acoustic component can be connected to VDD via at least one DC element,

The L/R connector of described the second acoustic component can be connected to GND via at least one the 2nd DC element,

The described L/R connector of described the first acoustic component and the described L/R connector of described the second acoustic component can be connected to each other via at least one AC element, and the described L/R connector of described the first acoustic component and the described L/R connector of described the second acoustic component can also be connected to the control FPDP of main frame or be connected to the 3rd acoustic component or electronic circuit.
23. systems according to claim 22, described system also comprises at least one set of two electronic audio frequency parts.
24. for from or to the interface system of at least one audio components flow transmission PDM data, this interface system comprises at least one acoustic component and comprises main frame or another acoustic component or the electronic circuit of controlling FPDP, wherein,

The L/R connector of described at least one acoustic component is connected to VDD or GND or is kept unsteady via at least one DC element, and,

The described L/R connector of described at least one acoustic component is connected to the control FPDP of described main frame or another acoustic component or electronic circuit via at least one AC element.
25. interface systems according to claim 24, described interface system is included at least two audio components in acoustic component separately, and described acoustic component is the first acoustic component and the second acoustic component, wherein,

The described L/R connector of described the first acoustic component is connected to VDD via at least one DC element,

The described L/R connector of described the second acoustic component is connected to GND via at least one the 2nd DC element,

The described L/R connector of described the first acoustic component and the described L/R connector of described the second acoustic component are connected to each other via at least one AC element, and

The described L/R connector of described the first acoustic component and the described L/R connector of described the second acoustic component are also connected to the control FPDP of described main frame or another acoustic component or electronic circuit.
26. interface system according to claim 24, described interface system comprises at least four audio components in acoustic component separately, and described acoustic component is the first acoustic component, the second acoustic component, the 3rd acoustic component and the 4th acoustic component, wherein,

The described L/R connector of described the first acoustic component and described the 3rd acoustic component is connected to VDD jointly via at least one DC element,

The described L/R connector of described the second acoustic component and described the 4th acoustic component is connected to the common L/R connector of described the first acoustic component and described the 3rd acoustic component jointly via at least one AC element, and

The common L/R connector of described the second acoustic component and described the 4th acoustic component is connected to the control FPDP of described main frame or another acoustic component or electronic circuit;

Or the described L/R connector of described the second acoustic component and described the 4th acoustic component is connected to GND jointly via at least one DC element,

The described L/R connector of described the first acoustic component and described the 3rd acoustic component is connected to the common L/R connector of described the second acoustic component and described the 4th acoustic component jointly via at least one AC element, and

The common L/R connector of described the first acoustic component and described the 3rd acoustic component is connected to the control FPDP of described main frame or another acoustic component or electronic circuit.
27. interface systems according to claim 24, wherein, described main frame is specifically programmed or is not specifically programmed as transmitting described control data.
28. interface systems according to claim 24, wherein, described at least one DC element and/or described at least one AC element are included in cut-off filter.
29. according to the interface system described in any one in claim 24 to 28, and described interface system also comprises biasing control or piece.
30. 1 kinds for from or to the method for at least one audio components flow transmission PDM data, the method comprises:

At least one electronic circuit is provided,

Described at least one electronic circuit is connected to described at least one audio components, at least one digital audio parts is provided thus,

The VDD connector that receives VDD electromotive force is provided,

Provide and receive the GND connector of numerical value lower than the electromotive force of described VDD electromotive force,

The CLK connector that receives the clock signal with high part and lower part is provided,

Provide from or to described at least one audio components or transmit the DATA connector of described PDM data from main frame and/or another this electronic circuit,

The L/R connector that receives DC electromotive force is provided, described DC electromotive force whether specify with the described high part of described clock signal or described lower part basic synchronization transmit, and

I/O circuit via described L/R connector transmission control data is also provided.
31. method according to claim 30, described method also comprises: the L/R connector of described at least one electronic circuit or digital audio parts is connected to and comprises main frame or another acoustic component or the electronic circuit of controlling FPDP.
32. methods according to claim 31, described method also comprises: the L/R connector of described at least one electronic circuit or described at least one acoustic component is connected to VDD or GND via at least one DC element or makes it keep floating, and the described L/R connector of described at least one acoustic component is connected to the control FPDP of main frame or another digital audio parts or another electronic circuit via at least one AC element.
33. methods according to claim 31, described method also comprises: at least two audio components in acoustic component are separately provided, described acoustic component is the first acoustic component and the second acoustic component, and the described L/R connector of described the first acoustic component is connected to VDD via at least one DC element, the described L/R connector of described the second acoustic component is connected to GND via at least one the 2nd DC element, the described L/R connector of the described L/R connector of described the first acoustic component and described the second acoustic component is connected to each other via at least one AC element, and the described L/R connector of the described L/R connector of described the first acoustic component and described the second acoustic component is connected to the control FPDP of described main frame or another acoustic component or electronic circuit.
34. methods according to claim 31, described method also comprises cut-off filtering.
35. methods according to claim 31, described method also comprises biasing control.
36. methods according to claim 30, wherein, carry out medium access control.
37. methods according to claim 31, wherein, also carry out error checking to described control data.
38. method according to claim 31, wherein, described electronic circuit produces random and/or fixing id number, and this id number is sent to main frame or another acoustic component or another electronic circuit via described L/R connector.
39. according to the method described in claim 38, wherein, this is to carry out before at least one the PDM audio signal operation after powering up and in described audio components or parts.
40. according to the method described in claim 39, wherein, the in the situation that of address conflict, described main frame repeats this processing until be provided the special one number of acoustic component with all audio frequency parts of described main-machine communication.
41. according to the method described in claim 40, and wherein, the special one number of each acoustic component is stored in the memory of described electronic circuit.
42. methods according to claim 31, wherein, whole described acoustic components carry out synchronous clock control by the described main frame that has been carried out for described acoustic component adjusting or acoustic component or electronic circuit.
43. according to the method described in any one in claim 30 to 42, wherein, and to each set of each single acoustic component and/or acoustic component control that gains.